AMP-activated protein kinase activates transcription of the UCP3 and HKII genes in rat skeletal muscle

1 The John B. Pierce Laboratory and 2 Department of Cellular & Molecular Physiology, Yale University, New Haven, Connecticut 06519; and 3 Research Division, Joslin Diabetes Center and Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02215 AMP-activated protein kinase (AMPK) has recently emerged as a key signaling protein in skeletal muscle, coordinating the activation of both glucose and fatty acid metabolism in response to increased cellular energy demand. To determine whether AMPK signaling may also regulate gene transcription in muscle, rats were given a single subcutaneous injection (1 mg/g) of the AMP analog 5-aminoimidazole-4-carboxamide-1- - D- ribonucleoside (AICAR). AICAR injection activated ( P